In many tropical and sub-tropical climates, it is quite common to see roof discoloration resulting from fungus or bacterial growth. This condition is addressed, for instance, in U.S. Pat. No. 3,494,727 and proposed to be solved by doping roof shingles with chips of metallic elements, the ions of which are capable of producing microbiological effects on microbes contacting the roof shingles. One of the metals mentioned for this purpose was zinc. See also U.S. Pat. No. 3,527,596 teaching the use of zinc granules.
In U.S. Pat. No. 3,479,130, the problem of retarding microbe growth in shingled roofs is confronted with the use of bimetallic strips capable of acting like an electrocouple, at least one of the metals selected being zinc.
Roof ridge ventilators, such as taught in my U.S. Pat. No. 4,325,290, are recognized as valuable and useful roof installations for achieving desirable ventilation of the space below the roof of the building. Such ridge ventilators usually are formed of aluminum or like structural metal which can be formed to the necessary shapes for the ventilator. Insofar as I am aware, such roof ventilators have never been formed of rolled sheet zinc material.
The ventilator of my patent has baffles 42 and 44 on opposite longitudinal sides thereof. The apertures 60, commonly known as weep holes, are provided in the baffles 42 and 44 at spaced distances one from the other along the length of the ventilator 10 to provide for moisture to drain from the ventilator 10 downwardly across the roof. However, it should be noted that the individual weep holes 60 are quite elongated and quite spaced apart. Thus, the liquid flow from this arrangement of holes 60 is intermittent and not sheet-like across the roof. Darkening and discoloration of shingled roofs because of fungus growth also occurs.